What is PXE?

PXE stands for Pseudo Xanthoma Elasticum. It is a hereditary disease that leads to the calcification of various tissues as a result of a defect on the ABCC6. This genetic defect means that the liver is unable to transport a vital substance to the bloodstream. Elastic tissue in the eyes, skin and blood vessels are very sensitive to accelerated calcification. The symptoms and the degree of seriousness vary from patient to patient. Because the disease is very rare, PXE is often not diagnosed immediately. It is estimated that between 400 and 500 people suffer from the disease in the Netherlands.

Explanation of PXE by Doctor vs Internet on KRO-NCRV television

Symptoms

PXE causes yellowish bumps or lesions in the folds of the skin, for example on the neck, the underarms, the back of the knees, groin, and elbow. It can resemble a skin irritation; the neck may appear unwashed. The skin may also sag in places. The dermatologist can use a biopsy to determine whether this is caused by PXE.

Older people may experience arteriosclerosis, a condition that is accelerated in PXE patients. The patient may experience pain when walking because of the hardening of the arteries in the legs. When they stop walking, the pain disappears (referred to as intermittent claudication). Walking therapy can reduce the symptoms.

As a result of the calcification of the blood vessels, PXE patients also have an increased risk of TIAs and brain hemorrhage.

PXE also results in calcification of the eyes. Small streaks occur in the retina, which causes tiny new blood vessels to grow. The retina often becomes very thin at the yellow spot (macula), which is the central point of vision. Both conditions often result in a considerable loss of vision. PXE patients should always be under the supervision of an ophthalmologist, who can use injections to help prevent poor vision.

The walls of the blood vessels in the stomach can also harden, resulting in an increased chance of stomach hemorrhage.

The above symptoms usually become evident around the age of 40. These symptoms may be different for every patient. Some patients have few skin lesions, and others have little or no loss of vision. Many patients have no stomach complaints and others have few vascular problems. It is impossible to predict how the disease will develop.

Heredity

PXE is the result of a hereditary defect on the ABCC6-gene. Dozens of mutations of this gene have now been identified, which can cause the disease. PXE is a recessive disease, which means that 2 defects must be present in the hereditary material in order to contract the disease. Children are generally only carriers, and will only develop the condition if both their father and mother are carriers, but do not suffer from the disease. The chance that such a child will develop the disease is 25%.

Pregnancy

Women with PXE generally have a normal pregnancy. There are no known complications for the fetus.

If a woman with PXE wants to become pregnant, she should tell her doctors. During the delivery and contractions there is risk of eye hemorrhage, but with proper monitoring this does not have to be a problem.